Description
libyang through 6.4.13 contains an uninitialized pointer free vulnerability in lydxml_env_netconf_rpc() in src/parser_xml.c when parsing NETCONF rpc action envelopes. Peers with a NETCONF session can send an action element containing non-whitespace text via lyd_parse_op() to crash servers like netopeer2 or corrupt the heap.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| CESNET | libyang | ≤ 6.4.13 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | libyang | No fix yet | — |
| Debian 13 | libyang | No fix yet | — |
| Debian 12 | libyang2 | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | libyang | No fix yet | — |
| Ubuntu 26.04 LTS | libyang | No fix yet | — |
| Ubuntu 24.04 LTS | libyang2 | No fix yet | — |
| Ubuntu 22.04 LTS | libyang +1 | No fix yet | — |
| Ubuntu 20.04 LTS | libyang | No fix yet | — |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | libyang | 3.13.6-4.1 | openSUSE-SU-2026:12301-1 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | libyang | No fix yet | — |
Advisories 1
- openSUSE-SU-2026:12301-1 libyang-devel-3.13.6-4.1 on GA media SUSE / openSUSE Security Updates · Oct 28, 2026
References
- https://github.com/CESNET/libyang/issues/2595 issue-tracking
- https://github.com/CESNET/libyang/commit/927fce908774289a7d9c07fff5704c33965c9773 patch
- https://github.com/CESNET/libyang/blob/v6.4.13/src/parser_xml.c#L1330-L1342 technical-description
- https://github.com/CESNET/libyang/blob/v6.4.13/src/parser_xml.c#L1196-L1224 technical-description
- https://hackmd.io/@haindpwn/libyang-netconf-rpc-envelope-uninit-free technical-description
- https://github.com/CESNET/libyang product
- VulnCheck Advisory: libyang through 6.4.13 Uninitialized Pointer Free in NETCONF RPC Parser third-party-advisory